| The solubilization of dodecylamine, dodecyl alcohol, sodium dodecylsulfate (SDS), and dodecyl trimethylammonium chloride (DTAC) in micelles of Triton X-100 (TX-100) was studied by viscosity measurements. Viscosity measurement allows one to distinguish between nearly spherical micelles and more extended micelles. High viscosity values result from the addition of nonionic surfactants to TX-100 solutions, and low viscosity values result from the addition of ionic surfactants to TX-100 solutions.; The proton spin-lattice relaxation time (T(,1)) of TX-100, 2-(2-ethoxyethoxy)-ethanol, and various mixed micelle systems, such as TX-100 dodecylamine, TX-100-dodecyl alcohol, TX-100-sodium dodecylsulfate, and TX-100-DTAC was investigated by the inversion recovery method. Also, the mathematical modeling of the NMR relaxation line shapes of the protons in the ethoxy chain in TX-100 was carried out. The hydrocarbon tail of the second ionic or nonionic surfactant presumably can penetrate to the aromatic ring in TX-100 micelle, but does not reach to the inside of the hydrophobic core. Also, ethoxy groups in TX-100 have different proton relaxation times. Those at the end of the ethoxy chain having longer T(,1)'s and presumably greater freedom of movement than those closer to the benzene ring.; The solvent sublation of diethyl, dibutyl, and bis(2-ethylhexyl) phthalates in a batch-type laboratory scale apparatus is reported. Removal of all three are accelerated by added NaCl and are decreased markedly by ethanol. The rate of removal of diethyl phthalate is much slower than the rates of removal of dibutyl and bis(2-ethylhexyl) phthalates.; Line shapes in gas chromatography were modeled by numerical integration of the differential equations describing mass transfer. The numerical dispersion which usually introduces substantial error into such calculations is greatly reduced by the use of any one of three so-called asymmetrical upwind algorithms for handling the advection term. The effects of the various parameters in the model, which assumes a Langmuir adsorption isotherm, are illustrated. |
